Magnetic coupling interaction-related photoluminescence behaviors in all-inorganic manganese chloride perovskites

Manganese halides , as dilute magnetic semiconductor materials , have magnetic coupling interactions that play an essential role in their photoluminescence (PL); however, such interactions remain controversial. A MnCl 3 ( A MC, A  = K, Rb, and Cs) and their hydrates A MnCl 3 ·2H 2 O ( A MCH, A  = K, Rb, and Cs) are both in the ABX 3 configuration but exhibit a wide variety of structures with different connectivity types and dimensions. Their magnetic coupling interaction has been demonstrated. However, few studies have systematically investigated the PL in conjunction with the magnetic coupling interaction over these chloride compounds. In this paper, the effect of the magnetic coupling interaction on A MC and A MCH PL is mainly revealed by temperature-dependent PL spectra and lifetimes. The Mn X 6 ( X 6  = Cl 4 (H 2 O) 2 or Cl 6 ) cluster connection types affect the Mn 2+ –Mn 2+ distances. The magnetic coupling interaction between Mn X 6 octahedrons affects the radiative transitions of manganese chlorides, which is influenced by the Mn 2+ –Mn 2+ distance, local symmetry, and water ligand. The Mn 2+ –Mn 2+ distance and the magnetic coupling interaction also affect their lifetimes. Variations in magnetic coupling interactions can shift emission wavelength , especially dual-emissions and near-infrared (NIR) emission at lower temperatures while A +  = K + . This work helps researchers understand the optical process of Mn 2+ ions in different manganese compounds and provides new insights into the design of tailored Mn 2+ ion phosphors.